A man who was found buried in a “clandestine grave” beneath a Colorado condo building was allegedly killed months ago by his partner-in-crime who believed he was a police informant, documents charge.

The body of Karl Beaman Jr., 36, was found beneath a slab of concrete in the crawlspace of the condo by police on Wednesday, according to the Aurora Police Department.

Haskel Leroy Crawford, 38, was arrested Thursday and charged with murdering Beaman six to eight months ago. The mother of his children, 29-year-old Casie Bock, was arrested Tuesday and charged with accessory to homicide after she allegedly helped Crawford hide the body.

On April 1, police received a call from one of Beaman’s relatives who was concerned they hadn’t heard from him since last May, which was unusual, according to an arrest affidavit obtained by Fox 31. 

The relative told police they had hired a private investigator who said his disappearance could be tied to Crawford because he and Beaman had been caught stealing catalytic converters.

According to the affidavit, a warrant had been issued for Beaman after he had been caught stealing the valuable car parts. 

Crawford was already booked into the Jefferson County Jail for charges of attempted first-degree murder related to another case when the warrant was issued.

Beaman’s relatives also started a Facebook page to help locate him. Through the page, a relative received an anonymous message.

“He’s buried under Casie Bock’s apartment in the crawlspace, under cement. Her and Leroy [Crawford] did it. I’m sorry,” the tipster wrote.

The tipster said the Bock had spilled the beans about the murder while she was high and told them Crawford had killed Beaman after accusing him of being a police informant, according to the document.

Police received another tip on April 3 with the exact same details Beaman’s relative had relayed to them.

When police met with the tipster, they said that they did not know Bock personally but their children went to school together. Bock asked the tipster three months ago if the person could watch her children and take them to school. They noted she appeared to be high on meth.

As Bock spiraled out of control in the last three weeks, she told the tipster Crawford killed Beaman inside their apartment and he was buried in a “shallow” grave beneath her building. The couple placed cement over the victim to help mask the smell, she said.

Bock said she didn’t help with the murder, but helped with the cleanup and moving the body, according to the affidavit.

When Bock was interviewed by police after her arrest, she told cops Crawford and Beaman “are best friends.”

She told police Crawford had just recently come back into her life. Then she returned home from work one day and found Crawford, with Beaman lying on the ground with a plastic bag over his head.

Bock said Crawford told her he killed him to protect his family. She threatened her if she did not help him move the body, she told police.

Beaman’s cause of death is pending a review by the Arapahoe County Coroner’s Office.